Art of casting and uniting metals.



A. M. CRAIG.

ART OF CASTING AND UNITING METALS.

APPLICATION FILED IAN.12, 1915.

Patented Sept. 1%, 1915.

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' UNITED STATES PATENT OFFICE.

ALVIN M. CRAIG, OF NEW HAVEN, CONNECTICUT, .ASSIGNOR TO METAL MOLDS COM- PRESSED CASTINGS COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

ART OF CASTING AND UNITING- METALS.

Specification of Letters Patent. Patented Sept. 14, 1915.

Application filed January 12, 1915; Serial No. 1,765.

To all whom it may concern .5

Be it known that I, ALVIN M. CRAIG, a citizen of the United States, and a resident of the city of New Haven, county of New Haven, and State of Connecticut, have invented a new and useful Improvement in the Art of Casting and Uniting Metals, of which the following is a full, clear, and exact description.

My invention relates to improvements in the art of casting and uniting metals so that a casting with an adhering piece, lining band or surface of metal of another kind than the main casting can be practically produced.

For many purposes it is desirable to have a casting provided with a band, surface, or portion of a different metal of a lower melting point than the casting, and it is difficult and expensive to produce such a casting with its adhering band or surface, and with the latter so closely united as to form practically a part of the casting. My invention is intended to obviate this difiiculty and produce a cheap, simple and efficient means of accomplishing the above result, and of getting a better casting and a more closely adhering surface or part that can be obtained by ordinary means.

One of the applications of my invention is to the manufacture of projectiles for all sizes of rifled ordnance. With projectiles of this kind it is customary to provide a band ordinarily of copper, which encircles the steel or iron projectile and which projects slightly from the surface of the latter so as to engage the rifling of the gun, as in case the hard metal engages the rifling of the gun, it is apt to quickly wear or break away. l Vhere the projectiles are grooved and a band of copper attached by the customary means, the operation is expensive and difficult. Great strain is applied to the band of softer metal when the gun is fired, and if the band is not absolutely tight and firmly united to the metal of the projectile it will slip or tear off with disastrous effect to the gun, and of course the projectile is propelled in an unsatisfactory manner. I have found, however, that by placing a ring of copper or other metal in a separable mold, made of metal or other material whlch rapidly radiates heat. and then pouring the casting in the mold so as to have it fill up around the band, the latter becomes praclutely rigid thereon. By using a separable mold made of material which is a good conductor of heat, the heat from the charge passes readily through the band and is radiated by the conducting mold so that the band comes out in perfect shape. Itis also necessary to have molds which can be readily separated, and I prefer to use a mold such as disclosed in Letters Patent of the United States No. 1,107,904, dated August 18, 1914.

While my invention is Well adapted to the cheap, rapid, and perfect production of projectiles as above stated, it will be readily seen that the same method can be applied to casting other articles which it is desired to encircle, surface, or line with a different metal. For instance an armor or other plate for a marine vessel can be cast by this method, so that a copper or other surface can be applied in the manner already indicated, or other metals can be united in this way.

Another important use of my improved method is to cast flanges for pipe connections with one or both provided with a surface of softer metal such as copper, so that when the flanges are united under pressure the softer metal will be mashed and form a perfect packing.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar reference characters indicate corresponding parts in all the views.

Figure 1 is a longitudinal section of a separable mold with a ring and charge therein showing how my method can be carried out. Fig. 2 is a View similar to Fig. l but with the mold provided with a core so as to cast a hollow projectile. Fig. 3 is a side elevation of a common form of projectile. Fig. 4 is a cross section on the line 4-4 of Fig. 3, showing one form of the conformation of the interior of the ring or band which is applied to the projectile by my method. Fig. 5 is a cross section of a twopart rectangular mold showing a means of casting a copper surface on a metallic plate. Fig. 6 is a broken detail view of the plate cast in accordance with the illustration in Fig. 5, and Fig. 7 is a cross section'of a pipe joint showing my improvement.

Referring to Figs. 1 and 2, I provide a metallic mold with separate parts 10 which can be operated in any usual or preferred manner, and the mold is provided with a cover 11 having a gate 12 and vents 13..

The mold is recessed slightly to receive a ring or band 15 which is usually of copper. The projectile 16 is cast in the mold, the parts of the mold being brought together and the charge poured in the usual way after the ring or band 15 has been inserted in the mold. The ring can be inserted cold, or can be first heated so as to expandit, in which case it will shrink with the charge. It is better to first heat the band to a-high temperature as this expands it so that 'it will contain more metal and thenit shrinks with the charge and becomes to all intents a part thereof. The charge chills quickly, and as both the band 15 and the mold sections 10 are good conductors of heat, the heat is quickly radiated and the band is uninjured and is fast to the projectile. If desired a squared section 17 can be cast on the point of theprojectile, so that it can be grasped by a lathe-chuck, and obviously the mold can be shaped so as to give the projectile its desired final construction. I prefer to provide a ring, or band with grooves 20 on its inner side, so that the molten metal of the charge 16 will fill the grooves, and thus make an exceedingly firm connection between the band and the casting. Obviously the inner surface of the band 15 can be made irregular in any other manner to give it more surface, or it can be left plain.

In Fig. 2 I have shown how a hollow projectile can be readily cast, in which case the gate 12 is placed nearer the side of the mold. and the cover 11 is provided with a core 18 in the usual manner, and with a suitable vent 14.

It will be understood that the particular form of the mold, so long as it is separable,

is not essential, and that the gate can be lo cated in any approved manner without affecting the invention.

In Fig. 3 I have shown the complete projectile 19, with its adhering band 15, and the cross sectional View of Fig. 4 shows the arrangement of the grooves in the band, but it will be understood that the mold can be madie to give the projectile any shape desire In Figs. 5 and 6 I have shown how my method can be used for casting a plate or ingot with a surface of copper or other metal oflower melting point than the plate or ingot; In this case the rectangular mold formed of separate sections 21 is used, and provided with a cover 22 and gate 23, and the coveris provided with a suitable vent 2- The copper or other surface metal 25 jured because the heat is radiated rapidly by it, and the mold and the ingot can be hammered or rolled after casting, precisely as if no surfacing metal were used.

It will be readily seen that by using a proper form of mold, a pipe, or vessel, or other structure may becast with an inner surface or lining, provided that the core is made of metal or other material that will quickly radiate heat, or any desired shape that is capable of casting can be given an exterio. surface in the same way.

From the foregoing description it will be readily seen how easily two difierent metals can be cast so as to form a perfect union and it will also be evident that copper and iron or steel can be readily cast'in this way, other metals can be united in a similar manner, and that the surfacing metal may extend entirely around the casting, or partly around,-or cover a small part of it as desired. It will also be obvious from the illus trations which I have given of the manner in which the invention can be used, that it can be applied to any form of structure which can be cast.

I claim:

1. The improvement in the art of casting metals, which consists in supporting an unmelted metallic part having a lower melting point in a mold which is a good conductor of heat, whereby said part is kept in substantially unfused condition throughout, and then pouring liquid metal forming the other part into said mold and in contact with the said first metal whereby a substantially finished article is produced.

2. The improvement in the art of uniting metals of different melting points, which consists in heating but not fusing a metal of lower melting point which is to be on the surface of the united parts, placing the heated metal on the inner surface of a mold which is a good conductor of heat, thereby providing against distortion of said metal of lower melting point, and then pouring the 3. The improvement in the art of casting a metallic body with an encircling band having a lower melting point, which consists in supporting the band in the inner wallof a mold which is a good conductor of heat, thereby providing against the fusion and distortion of said band, and then pouring the charge in the mold so as to fill the band and envelop the edges thereof, whereby a substantially finished article is produced.

The improvement in the art of casting a metallic body with an encircling band having a lower melting point, which consists in heating and thereby expanding the band to a high temperature but not fusing it, supporting the same in a mold which is a good conductor of heat, thereby providing against its distortion, and then pouring the charge into the mold and band, whereby the charge and band become united and will shrink together when cooling.

5., The improvement in the art of casting a substantially nnished metallic body with {H encircling band having a lower melting point, which consists in supporting the band in a mold which is a good conductor of heat, thereby providing against the distortion of the band, and then pouring the charge in the mold so as to fill the band, whereby the charge and band become united.

6, The improvement in the art of uniting a metallic part with another cast metal part having a higher melting point, which consists in casting the metal having the higher melting point in contact with the unmelted metal having the lower melting point, which latter metal has been given essentially the desired. shape, and conducting the heat from the unmelted metal with sufiicient rapidity" to prevent its fusion or distortion.

7. The improvement in the art of uniting metals having different melting points, which consists in heating but not melting the metal having the lower melting point, casting the metal having the higher melting point in contact with the said unmelted metal which has been given its desired shape, and conducting the heat away from the latter with sufficient rapidity to prevent its fusion or distortion.

8. The improvement in the art of casting a substantially finished article composed of a plurality of metals having different melting points, which consists in first shaping the metallic part having the lower melting point, supporting said metallic part in a metal mold, thereby providing for the rapid radiation of heat and the smooth finish of the charge, and then pouring the melted metal having the higher melting point/into the mold and in contact with said first metal, whereby the two metals become united.

' ALVIN M. CRAIG.

Witnesses:

WARREN B. Huronmson, J. ASPINWALL Hones. 

